1. Field of the Invention
This invention relates to heat transfer fluids. In one aspect, this invention relates to aryl ether heat transfer fluids. In another aspect, this invention relates to heat transfer fluids comprising aryl ethers and polyphenylphenols.
2. Description of the Prior Art
The components of the present invention are known. Jackson et al. teach in U.S. Pat. Nos. 3,888,777, 3,907,696 and 3,966,626, various heat transfer fluids comprising certain of the components used herein, particularly diphenyl ether, 2-biphenylylphenyl ether and 4-biphenylylphenyl ether. However, these heat transfer fluids also comprise such components as biphenyls and polyphenyl ethers which are not present in the instant invention. Moreover, these heat transfer fluids do not have the unusually good fluidity of the instant invention at low temperatures (0.degree. C. and below).
Copending application by Watson et al., entitled "HEAT TRANSFER FLUIDS HAVING A LOW FREEZE POINT" and filed even date herewith, teaches a heat transfer fluid comprising diphenyl ether, 2-, 3- and 4-biphenylylphenyl ether, and polyphenylphenols in various proportions. The present invention differs from the Watson et al. invention by the relative amounts of polyphenylphenol and 3-biphenylylphenyl ether.